Cotton Plugs: The Obscure, Yet Critical Material for Medical and Scientific Needs


Richmond Dental & Medical develops new products that are, by nature, of medical grade quality. These innovations often  see use in other marketplace applications that require the same product attributes as the practice of medicine or dentistry. The cotton plug is an example of one such innovation.

Cotton plugs, similar to cotton rolls, but not confined to a specific length or diameter, typically pulled from cotton rolls, are the physician, dentist, and lab researcher’s best friend when working with flasks, test tubes, and other vessels to preserve specimen integrity.

When medical, dental, and research professionals look to keep a culture intact, cotton plugs are the go-to soft cap for culture preparation and protection.


What Are Cotton Plugs?

Tight plugs are not advisable for plant and bacterial cultures, which require the maintenance of an aerobic environment, which is characterized by the presence of free oxygen. Loose-fitting caps, like cotton plugs, permit the free passage of air over the edge of tubes and flasks and prevent the lack of air flow that causes semi-anaerobic conditions in the culture.

In general, cotton plugs are used to stop air movement that might carry microbes. They are sometimes used in equipment when sterilized in an autoclave, as well as  in the tops of agar flasks in the autoclave. They are used in test tubes, again to prevent contamination through the air.

Culture vessels like flasks and tubes must stay aerated in order to prevent accumulation of certain gaseous compounds, such as ethylene. A plant hormone, ethylene is normally produced and released in the general proximity of a plant. As ethylene accumulates,  Accumulation of ethylene leads to certain developmental abnormalities that can be observed in plant culture when the vessels are not properly aerated. Cotton plugs are usually sufficient to keep fungal infection from penetrating inside the vessel while still allowing for proper aeration.


What Industries Use Cotton Plugs?

Not surprisingly, cotton plugs see use in several industries that need to keep cultures and natural specimen preserved for microbiological testing and analysis.

Entomologists,  as well as laboratory professionals utilize cotton plugs in culture vessels. In addition to these professionals who treat the human condition, entomologists--scientists who study insects, also widely use cotton plugs.


What Are Some of the Most Common Use-Cases for Cotton Plugs?

Scientific professionals love using cotton plugs in culture vessels like flasks and tubes, because cotton plugs preserve the culture’s integrity through the allowance of air flow, while shielding the culture from dust and other microorganisms. The natural wicking ability of purified cotton makes cotton plugs ideal for chemistry applications.

Entomologists use cotton plugs with regard to field specimen capture of insects, to preserve the biological integrity of each specimen for lab testing and analysis.


How Do Cotton Plugs Differ From Other, Similar Products?

Most often, the soft-cap alternative to cotton plugs is made of silicone. A silicon polymer, silicone is rubberized for flexibility. While cotton is natural and biodegradable, silicone will not degrade. However, silicone easily recycles for other uses.


Quality of Richmond's Cotton Plugs

Cotton plugs taken from Richmond Dental and Medical’s purified cotton  is a superior choice for medical, dental, and scientific professionals looking to preserve culture and specimen for testing and analysis. Our commitment to quality has yielded rolls made from Purified Cotton, which is highly absorbent and high-performing in their allowance of air flow while preventing microbial passage into the culture vessel.

Even better, our rolls are fully autoclavable, for repeat sterilization prior to cotton plug use. Richmond purified cotton plugs  are an inexpensive option for culture vessel use.